Propeller



UNITED STATES PATENT OEEICE,N

ALBERT L. KRAUS, OF PEABODY, MASSACHUSETTS.

PROPELLER.

SPECIFICATION forming part of Letters Patent No. 574,096, dated December 29, 1896.

4 Application iiled April 6, 1896. Serial No. 586,313. (No model.)

To all whom, it may concerns' Be it known that l, ALBERT L. Kanus, a citizen of the `United States, residing. at Peabody, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Propellers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to an improvement in screw-propellers, and more especially to that class of screw-propellers wherein a series of blades are employed, the screw-blades being arranged in a spiral around the shaft.

The invention contemplates the employ ment of a series of sets of blades of varying sizes, the larger members being arranged in advance of the smaller members, and the construction of the smaller or outer blades in a manner to increase their surface area.

The invention is embodied in the construction illustrated in the accompanying drawings, wherein like letters and figures of reference designate corresponding parts in the several views, and in Which- Figure lis an elevation of the improvement. Fig. 2 is a diagram showing the relative lengths of the blades, and Fig. 3 is an end elevation.

In the construction and arrangement of propellers of this class `heretofore it has been Y customary to arrange the greater or larger blades at the rear and the smaller blades at the front adjacent the bearing. This arrangement necessitates the employment of an outer or rear support or journal-box and, as is obvious, places the greater strain on the outer end of the shaft at a point considerably beyond the main bearing. The larger blades being so arranged would tend to twist or bend the shaft. By my construction I have overcome these defects and at the same time increased the power of the screw,

I n the drawings, A designates the stuflingbox or journal-bearing in the stern of the vessl, which latter is designated by the letter The shaft is represented at C and is supported wholly by the box or bearing A, its outer end being free or without an independent support. On shaft C are the blades l la,

2 2, 3 3f", and 4 LF. The respective blades are arranged in .pairs or sets, one blade of each set being diametrically opposite the other and each set carried by a collar D, made fast to the shaft in any convenient manner. 'Ihe blades of each set are properly inclined to ser-ure the desirable screw eect and each is tapered, as is usual, at its end. The blades 2 2fL are shorter than the larger `blades l ln and are arranged to extend beyond the plane of the edge of the larger blades, while the blades 3 3 are proportionally smaller and arranged in the same relation to the blades 2 2a as the latter are to the blades l l, a spiral arrangement being thus secured. The outer or smaller blades 4 Lt are ot' a width greater than the relative width of the other blades, as is clearly shown in Fig. 8.

By the special arrangement of blades and their graduated sizes it will be seen that two lines of tapered spirals are formed.

In arranging the sets of blades they are spaced apart a suiiicient distance to permit a wall or body of Water to occupy the space in the immediate rear of each blade, which will be of sufficient volume to furnish full and ample resistance to the neXt succeeding screw or blade. In fact I have found that the power of the screw in the order above described is much greater than ,in the reverse order, and

by the arrangement of blades relative to each other in the manner shown the full force and effect of each blade is secured. The larger or master set, it. will be seen, has the full effect of the resistance, While the smaller blades act with proportionate effect owing to their spiral arrangement, and the distance between which is occupied practically by a stationary body of water. The outer short blades, as stated, are of a transverse length or breadth greater in proportion than that of the other blades. By this means a larger area is secured and the leverage or strain on the shaft is not materially increased.

It is to be understood that the special arrangement of the blades in pairsis the pre ferred form, although the invention is not necessarily limited to such an arrangement,

as any convenient number of blades in the` ICO Having thus described my invention, what being in advance of the others, substantially 1c is Claimed as new, and desired to be secured as described.

by Letters Patent, is- In testimony whereof I aix my signature The combination with a shaft, of the gradin presence 0f two Witnesses. 5 uated series of sets of blades spaced apart ALBERT L KRAUS and secured on the shaft, the blades of the outer set being proportionately of greater lVitnesses:

Width from side edge to side edge than those CHAs. NV. PARKER, of the other sets, and the set of larger blades L. S. BACON. 

